Reply #20: Julian May's "Saga of Pliocene Exile"

[Orrex]

I read it almost 20 years ago, and I can't remember whether I'd care to read it again, but there you have it.

The basis for the series involves a one-way time portal to the distant past.



Also, Crichton's wholly unreadable Timeline involves an archaeologist getting stuck in the past and his team going back to rescue him.
Spoiler: In the end, one of his colleagues semi-voluntarily elects to stay in the 14th century